I bought and just finished building a B.87 EX X2. Great piece of kit and now I am not afraid of working with SMD components! Everything is working (more or less… Cherry MXs are not consistent with the clicks), even the RGB LEDs are all working. However, the LEDs on each key are way too dim. I purchased “purple” LEDs from Ebay, and you had recommended 820 ohms, which works. I would like to lower the resistance to increase the voltage and current for each LED.

I know 330 ohm is too low from your FAQ. What is the lowest resistor rating you can recommend?

We recommend 820 ohm resistors as the lowest one,
since our PCB supports both in-switch LED and RGB LED.
USB has a currency limit.
If you set in-switch LED too bright, it doesn’t anything but would-be malfunction.

I did some checking with my multimeter. The RGB LEDs are using 62 mA at all brightness levels (1 to 255 on bootmapperclient). When RGB LEDs are at level 1, in-switch uses 5 mA. When RGB LEDs are at 255, in-switch uses 1 mA.